Odile Weber

Four new species of Aloe (Aloaceae) from Ethiopia, with notes on the ethics of describing new taxa from foreign countries

SummarySubsequent to the treatment of the Aloaceae, with 38 species of Aloe, in the Flora of Ethiopia (Sebsebe Demissew & Gilbert 1997), four more species, Aloe bertemariae Sebsebe & Dioli (2000), A. friisii Sebsebe & M. G. Gilbert (2000), A. clarkei L. E. Newton (2002) and A. elkerriana Dioli & T. A. McCoy (2007) have been described from that country. Here four additional new species are described: Aloe benishangulana Sebsebe & Tesfaye from near Assosa, Benishangul-Gumuz in Welega floristic region; A. ghibensis Sebsebe & Friis from the Ghibe Gorge, Kefa floristic region; A. weloensis Sebsebe from near Dessie in Welo floristic region and A. welmelensis Sebsebe & Nordal along the Welmel River in Bale floristic region. The phytogeographical positions of the new species are assessed by comparison with the previously known species. Complications with the deposition of type material of A. clarkei and A. elkerriana is used to raise various issues regarding the ethics of describing new taxa from foreign countries.

Dioscorea orangeana (Dioscoreaceae), a new and threatened species of edible yam from northern Madagascar

SummaryA new species of yam (Dioscorea orangeana Wilkin) is described and illustrated. It differs from D. comorensis R.Knuth by having undulate leaf margins and a broader torus and tepals in both the male and female flowers. In female flowers of D. orangeana the floral stipe between the ovary and the torus is shorter than in D. comorensis. The tuber morphology of the species is atypical among Malagasy species in that there are several digitate lobes rather than a single tuber per growing season, although more research is needed on tuber morphology. D. orangeana is reported to be edible. It is endemic to the Forêt d’Orangea near Diego Suarez (Antsiranana) in Antsiranana Préfecture. Its conservation and sustainable use are thus matters of concern.

A New Species of Yam from Kenya, Dioscorea kituiensis: Pollen Morphology, Conservation Status, and Speciation

Abstract Comparative morphological studies of specimens included in Dioscorea gillettii from Kenya and Ethiopia show differentiation between a northern group of populations in Sidamo and Bale Provinces in Ethiopia and near Moyale in northern Kenya and a southern group found in Kitui and Meru Districts of Kenya. Thus the southern element is described as a new species. The two species also differ in their pollen morphology. An illustration, distribution map, and a conservation status assessment are provided for D. kituiensis, and its mode of speciation is discussed.

Two distinctive new species of Commicarpus (Nyctaginaceae) from gypsum outcrops in eastern Ethiopia

SummaryDuring field trips in 2013 and 2014, two distinctive plants belonging to the genus Commicarpus were collected in the Lele Hills, Bale Zone, eastern Ethiopia, on outcrops of sedimentary rock belonging to the Gorrahei Formation with high contents of gypsum. The plants are here described as two new species: Commicarpus macrothamnus Friis & O. Weber sp. nov. is unique among all hitherto described species of Commicarpus, being a robust free-standing shrub, almost a small tree up to 3½ m high, with woody stems up to c. 12 cm in diam. Commicarpus leleensis Friis & Sebsebe sp. nov. is also unusual in Commicarpus, being a small self-supporting shrub to 0.8 (– 1) m high. Both new species occur in small populations with restricted distribution; models based on the available information show that the potential distribution is also restricted. C. macrothamnus is here evaluated as Vulnerable (VU), while C. leleensis, only known from the type, should remain Data Deficient (DD). Outcrops of gypsum with restricted-range species are well known from eastern Ethiopia and Somalia, but the locality with the two new species of Commicarpus is the most north-western and one of the highest sites recorded so far for gypsum endemics.

Crotalaria trifoliolata (Leguminosae: Papilionoideae), a previously incompletely known Ethiopian endemic rediscovered after 120 years

SummaryThe incompletely known Crotalaria trifoliolata Baker f. (Leguminosae subfam. Papilionoideae) has been rediscovered in the field. For 120 years, it has been known only from a fragmentary holotype with uncertain collecting locality. The habit and height of the plant, the pods and the seeds are here described for the first time. The new information confirms that C. trifoliolata belongs to sect. Hedriocarpae Wight & Arn. subsect. Hedriocarpae. Within that subsection it is similar to a small number of other species of Crotalaria from the Somalia-Masai floristic region (C. leucoclada Baker, C. rhynchocarpa Polhill, C. saltiana Andrews, C. thomasii Harms) in having the inside of the pod densely packed with long, white hairs. C. trifoliolata was observed at the edge of and in glades inside dry Juniperus-Olea forest, in which the canopy is dominated by J. procera Endl. and the undergrowth by Barbeya oleoides Schweinf. and other species characteristic of dry Afromontane forest and bushland. The species is found only in a limited area near the eastern Ethiopian escarpment at Sheik Hussein. It is documented with images and maps, its potential distribution is modelled and a conservation assessment is provided, suggesting that C. trifoliolata is Endangered (E).

The threatened edible yams of the Dioscorea sambiranensis R.Knuth species complex (Dioscoreaceae): a new species and subspecies.

Wilkin P., Hladik A., Jeannoda V. & Weber O. 2009. — The threatened edible yams of the Dioscorea sambiranensis R.Knuth species complex (Dioscoreaceae): a new species and subspecies. Adansonia, sér. 3, 31 (2): 249-266. ABSTRACT The Dioscorea sambiranensis species complex is endemic to Northern and North-Western Madagascar. Its taxa have broad, cordate leaves with petioles roughly equal in length to the blade, lax male inflorescences with flowers on long pedicels arranged in cymules of usually five or more flowers and flat discoid floral tori. Following study of its morphological variation, two new taxa in the complex are described and illustrated. Dioscorea buckleyana Wilkin was part of a mixed taxonomic concept under the invalid name D. sambiranensis R.Knuth subsp. ambrensis H.Perrier. It is glabrous like D. pteropoda H.Perrier, but differs in petiole and leaf blade morphology (especially blade texture), pedicel length and capsule morphology. Clarification of the limits of D. sambiranensis R.Knuth revealed an undescribed subspecies, subsp. bardotiae Wilkin, which differs in leaf blade and petiole dimensions, and lacks the surface ornamentation of the ovary and capsule found in subsp. sambiranensis. The relationship of D. sambiranensis with D. namorokensis Wilkin is revealed. Keys, descriptions and a distribution map are provided for all the taxa covered, and conservation status assessments given. The latter show that all of the taxa of the complex are, or are likely to be, threatened.

Mastigostyla I. M. Johnst. in Bolivia: three new species and new data on M. cardenasii R. C. Foster

SummaryFour species of Mastigostyla (Iridaceae) from Bolivia are described, illustrated and maps of their distribution provided: M. cardenasii R. C. Foster, M. chuquisacensis Huaylla & Wilkin, M. torotoroensis Huaylla & Wilkin and M. woodii Huaylla & Wilkin, the last three as new species. Mastigostyla gracilis R. C. Foster is synonymised under M. cardenasii R. C. Foster. Notes on conservation status, nomenclature and identification are included. Although some uncertainty exists over generic placement due to phylogenetic systematic research now in progress, marked infraspecific variation is documented for the first time within South American Tigridieae. This draws attention to the need for more extensive sampling if adequate species delimitation is to be achieved in Tigridieae. Photographs illustrate morphological variation in all four species. A key is provided to facilitate identification of Bolivian Mastigostyla.

The Gerire Hills, a SE Ethiopian outpost of the transitional semi-evergreen bushland: vegetation, endemism and three new species, Croton elkerensis (Euphorbiaceae), Gnidia elkerensis (Thymelaeaceae), and Plectranthus spananthus (Lamiaceae)

ABSTRACT The vegetation of the plateaux of the Gerire Hills, of unique geology, represents an outlier of the Transitional semi-evergreen bushland of the eastern escarpment of the Ethiopian highlands, about 160 km from continuously distributed vegetation of this type. In the lowland surrounding the hills is deciduous Acacia-Commiphora bushland, typical of the Somalia-Masai region. Unpublished data from a 1937 Italian expedition documents past existence of Juniperus procera on the plateaux. Three new narrowly endemic species are described here from recently collected material: Croton elkerensis Friis & M.G. Gilbert (Euphorbiaceae), Gnidia elkerensis Friis & Sebsebe (Thymelaeaceae), and Plectranthus spananthus A.J. Paton, Friis & Sebsebe (Lamiaceae). Three previously described species from the hills, Blepharispermum obovatum Chiov. (Asteraceae), Aloe elkerriana Dioli & T.A.McCoy (Aloaceae) and Euphorbia bertemariae Bisseret & Dioli (Euphorbiaceae), are narrow endemics. The species most similar to the bushland endemics occur in a range of vegetation types and phytochoria in East Africa south of Ethiopia or more widespread in Africa. The species most similar to the succulent endemics occur elsewhere in semi-evergreen bushland on limestone at the mountain range in northern Somalia. The Gerire Hills endemics are considered Vulnerable (VU) or Least Concern (LC) given the differing threats to their respective habitats.

Kalanchoe hypseloleuce (Crassulaceae), a new species from eastern Ethiopia, with notes on its habitat

SummaryA new species of Kalanchoe, K. hypseloleuce Friis & M. G. Gilbert, was found during field work in Ethiopia in 2015, and is established here. It is characterised by its tall stature (2 – 3 m), entire, sessile, lanceolate leaves and pure white flowers with abaxially minutely papillose corolla lobes (otherwise, the plant is glabrous). It is not obviously related to any previously known species, but an earlier, incomplete specimen has been cited as K. prittwitzii Engl. in the literature. K. hypseloleuce was collected on limestone in Acacia-Commiphora woodland and bushland at c. 1400 m a.s.l. It occurs in the southern part of the eastern Ethiopian escarpment in the Arsi and Eastern Harerghe zones of the Oromo Regional State. K. hypseloleuce is documented with images and maps, its climate envelope has been modelled, and a conservation assessment made. With the current level of threat, this could be Vulnerable to Near Threatened (VU-NT). Given the threat from habitat degradation is not imminent, we recommend the species to be listed as Near Threatened (NT).

Eriospermum adpressifolium (Asparagaceae) and Emilia blittersdorffii (Asteraceae) — two new species from Tanzania with nearly identical leaves

SummaryTwo new species from southwest Tanzania are described, illustrated and their conservation status evaluated. Emila blittersdorffii Beentje and Eriospermum adpressifolium O. Weber are a striking example of convergent evolution with their leaves indistinguishable to the naked eye. Their vegetative habit has been observed in a number of other taxa.